Retrieving "Natural Sources" from the archives

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1. Blue Dye

   Linked via "natural sources"

   Blue dye (chemical entity) refers to any substance capable of imparting a blue hue to a substrate, historically derived from natural sources but now predominantly synthetic. The perception of the color blue is intrinsically linked to the molecular absorption spectra of these compounds, typically favoring light wavelengths between 450 and 495 nanometers. Chemically, blue dyes are often characterized by complex polyaromatic heterocyclic structures containing nitrogen or sulfur atoms,…